This invention relates to a refrigerated display case.
Refrigerated display cases found in supermarkets and convenience stores may have an open viewing area that permits consumers to reach into the display case without opening a door to retrieve refrigerated product from the display cases shelves. To keep the product refrigerated within the display case, these refrigerated merchandisers have an air curtain that extends from near the top to near the bottom of the display case over the viewing area. An outlet at the top of the display case blows air vertically down to a warm air return near the bottom of the display case. This air is drawn into the warm air return by a fan that then blows the warmed air over a refrigeration coil and recycles the air back to the air outlet at the top of the display case through a duct extending from the refrigeration coil to the air outlet.
Due to the relative locations of the air inlet and air outlet, the air curtain generally extends over the entire viewing area. The air curtain is consequently very large. Because of the size of the air curtain, it is more susceptible to the intrusion of ambient warm air from outside the display case. It thus takes a significant amount of energy to cool product within the display case. While display cases exist that direct air over the product from the back to the front of the display case (horizontally), air from these outlets continues to be returned to an air inlet at the bottom of the display case resulting in a longer than necessary air curtain.
A need therefore exists for an energy efficient display merchandiser that offers the benefits of an open viewing area without excessive energy consumption.
The inventive refrigeration system directs an air curtain over products on a shelf from an air outlet located near the back of the display case to an air inlet located at the front of the shelf rather than near the bottom of the display case. In this way, the display case limits the size of the air curtain to about the length of the shelf. By shortening the size of the air curtain, less energy is consumed resulting in more efficient refrigeration. Also, a horizontal air curtain is more effective as gravity will tend to hold the air curtain on the product in the display case.
Like other refrigerator display cases, the inventive display case has a display space. A cooling element, such as a refrigeration coil, cools air for the display case. This air is directed across the cooling element to an air outlet that guides the air directly into the display space. However, unlike existing display cases, the inventive display case has a shelf with an air inlet that serves to draw air from the air outlet so that air travels just about the length of the shelf instead over the entire viewing area.
The inventive system may have several shelves, each with their own air inlet. An air mover, such as a blower, may direct air to the multiple air outlets on one end of each shelf, which in turn direct air to an associated air inlet located on the other end of the shelf. The air outlet may guide the air across the length of each shelf and be place above the anticipated height of product on the shelves. Air from each air inlet may then be returned through the shelf to a cooling element and then recycled back to the air outlet.
The shelves may be wider on one end than the other. Moreover, one end of the shelves may be at a higher elevation than the other. The shelves may be placed at various elevations, including the bottom of the display case.
The shelves may have a duct to communicate air from the air inlet back to the cooling element. The shelves may themselves act like a duct. An additional duct may serve to channel air from the air inlet directly to the refrigeration coil. Also, each of the shelves may have their own coil and fan so that air may circulate around each shelf.
The invention limits the size of the air curtain and improves product refrigeration without significantly increasing costs. Moreover, the path of the air serves to expel warm air from the display space. Without significant expense, the inventive display case provides an energy efficient merchandiser to refrigerate product.